This invention generally relates to devices used to rejoin a human sternum that has been severed longitudinally, and more particularly relates to such devices that function in a clamping manner to retain the severed sternum portions in a closed and abutting relationship post-operatively.
It is often necessary in surgical operations to longitudinally sever the patient's sternum so that the ribs may be spread to provide access to internal organs such as the heart. It is then necessary to secure the sternum halves together for post-operative recovery. Various closure techniques are used to accomplish this task. For example, holes may be drilled into the sternum halves and suture material passed through and tightened to cinch the sternum halves together. Apertured plates may be added to further rigidify the sternum post-operatively, with the suture material being passed through the apertures in the plate and the sternum. Encircling members may be wrapped around the sternum and tightened. Toothed bridging members extending across the cut line may be pressed into the sternum surfaces and/or secured with threaded rods extending between the sternal halves.
Another sternal closure technique involves the use of clamps having hook-like projections or engagement members on both ends, the clamp being positioned laterally relative to the sternal incision with the projections being disposed between adjoining rib pairs. The clamp is then linearly contracted or compressed to shorten the device and force the sternal halves together, the clamp typically comprising two members joined in a linear telescoping manner. Locking or securing means, either permanent or releasable, maintain the clamp in the contracted configuration.
Examples of such techniques and devices are described in U.S. Pat. No. 3,473,528 to Mishkin et al., U.S. Pat. No. 4,201,215 to Crossett et al., U.S. Pat. No. 4,279,248 to Gabbay, U.S. Pat. No. 4,583,541 to Barry, U.S. Pat. No. 5,139,498 to Astudillo Ley, U.S. Pat. No. 6,051,007 to Hogendijk et al., U.S. Pat. No. 6,217,580 to Levin, U.S. Pat. No. 6,302,899 to Johnson et al., U.S. Pat. No. 6,540,769 to Miller, III, and U.S. Pat. No. 6,712,821 to Gabbay.
It is an object of this invention to provide a sternal closure clamp device having the functionality of a contractible sternal clamp, such that the sternal halves may be quickly and easily pressed or drawn together in a sliding or telescoping manner and retained in position, but which provides greater reinforcement and rigidity to the severed sternum. It is a further object to provide such a sternal closure clamp device where the stress applied against the sides of the sternal halves is more widely dispersed than with conventional clamps. It is a further object to provide such a sternal closure clamp device whereby a single device is secured in two inter-rib spaces on each side of the sternum rather than in just one inter-rib space on each side. It is a further object to provide such a sternal closure clamp having four engagement members that are each disposed between different rib pairs, wherein the engagement members contract and extend in a direction non-perpendicular to the sternal incision, such that the clamp device is generally X-shaped. It is a further object to provide an embodiment of a sternal closure clamp device wherein the engagement members are pivotable such that the relative angles of the engagement members can be varied. It is a further object to provide an embodiment of a sternal closure clamp device wherein the engagement members are extendible and contractible independently. It is a further object to provide an embodiment of a sternal closure clamp device wherein the engagement members are extendible and contractible in unison utilizing a single control mechanism.